A center pillar provided in a vehicle such as an automobile includes an outer panel that is exposed on the outer surface of a lateral portion of a vehicle body, and an inner panel that is joined to the outer panel on a compartment side. In some cases, a reinforcement is further interposed between these panels.
In general, the center pillar has a shape that is curved or inclined toward the vehicle interior side as the center pillar extends from the vicinity of the so-called belt line toward the upper end, as viewed from the vehicle front side. Therefore, the curvature of the center pillar is at its maximum near the belt line, and when a load is input to the center pillar from the vehicle upper side or a vehicle lateral surface, the center pillar is easily deformed near the belt line.
Japanese Patent Laid-open Publication No. 2011-219014 A describes a center pillar structure including a belt anchor reinforcement to which a seat belt anchor is fixed in addition to an outer reinforcement that is disposed so as to extend along the outer panel. The outer panel and the inner panel each include a front flange and a rear flange that are disposed across a gap in a vehicle front-rear direction and that are elongate in the vertical direction. The belt anchor reinforcement connects the front flange and the rear flange in a straight line in the vehicle front-rear direction. Japanese Patent Laid-open Publication No. 2011-219014 A states that it is possible to improve proof stress with respect to loads input from the vehicle upper side by adding the belt anchor reinforcement to the center pillar.
Japanese Patent Laid-open Publication No. 2012-136190 A describes a center pillar structure including an outer reinforcement that is disposed between the outer panel and the inner panel and that has a projecting portion and a recessed portion. In the outer reinforcement, the height of the projecting portion or the depth of the recessed portion is at its maximum at the belt line, and the height of the projecting portion or the depth of the recessed portion is reduced as the outer reinforcement extends from the belt line toward the vehicle upper side or the vehicle lower side. Japanese Patent Laid-open Publication No. 2012-136190 A states that by disposing such an outer reinforcement, the center pillar is hard to deform when loads are input from the vehicle lateral surface.
However, although the center pillar structure described in Japanese Patent Laid-open Publication No. 2011-219014 A is thought to have improved proof stress with respect to loads input from the vehicle upper side, there is a possibility that the center pillar structure is easily deformed with respect to loads input from the vehicle lateral surface. In addition, weight and cost are increased as the belt anchor reinforcement is added.
Although the rigidity of the center pillar structure described in Japanese Patent Laid-open Publication No. 2012-136190 A is improved by gradually changing the shape of the projecting portion and the recessed portion of the outer reinforcement in the vehicle vertical direction, there is a possibility that the inner panel is deformed when loads are input from the vehicle upper side or the vehicle lateral surface.
In view of the foregoing problems, it is an object of the present invention to provide a center pillar structure with which the rigidity of the inner panel can be ensured and the deformation near the belt line can be suppressed when loads are input.